Plant Community Composition and Structure of Asabot Dry
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y & E sit nd er a iv n g Tura et al., J Biodivers Endanger Species 2017, 5:4 d e o i r e B d Journal of DOI: 10.4172/2332-2543.1000202 f S o p l e a c ISSN:n 2332-2543 r i e u s o J Biodiversity & Endangered Species Research Article Open Access Plant Community Composition and Structure of Asabot Dry Afromontane Forest, West Harare Zone, Ethiopia Tura TT*, Soromessa T, Leta S and Argaw M Center for Environmental science, Addis Ababa University, Ethiopia Abstract Dry Afromontane forests are the most altered and threatened ecosystem. Indeed, having a diverse ecosystem and biodiversity designated as a priority site in conservation. The objective of this study was to demonstrate plant community structure, regeneration status, and conservation priority species. The study was conducted on Asabot mountain forest which is found in West Harare Zone, Oromia National Regional State, Ethiopia. The vegetation sampling was designed at clustered altitude through mixed spatial stratified-random sampling method to ensure a full coverage of environmental variation and habitat heterogeneity. The main parameters used in vegetation characterization was diameter at breast height (DBH), height, seedling, and sapling of wood species recorded at sampled quadrat. The study analyzed plant community indicator species, importance value index, and vegetation structure and regeneration status, and conservation priority of selected species. The plant community was described by 97 species of 90 genera and 52 families. The result showed that eight specific trends and three general trends of population structure based on DBH, seedling, sapling and mature trees or shrubs. The dominant classes of the Asabot dry Afromontane forest were small trees and shrubs which is an indication of secondary vegetation. The conservation priority classification and visual field observations of some woody species were required urgent management intervention. Furthermore, the detail botanical aspects of the forest, the reason for the absence of regeneration in some tree species and socio-economic aspect of the vicinity is strongly recommended farther research in order to inaugurate appropriate management intervention. Keywords: Dry afromontane forest; Plant community; Indicator present study intended to analyze plant community, forest structure, species; Structural analysis; Regeneration status and regeneration status of some woody species in order to forecast conservation priority and appropriate management. Introduction Methods and Materials The natural gifts of African countries with high endemism of animal and plant species passionate by Ethiopia diverse agroecology [1]. The Study site description agricultural extensive and excessive deforestation hampered natural Asabot mountain forest is located in Miso district of West Harare regeneration and seedling establishment that affected the diversity Zone, Oromia Regional state, Ethiopia (Figure 1). Geographically, the and structure of plant communities in most tropical forests [2-4]. In a study site is located at 40° 31’30 to 40° 42’0E and 9° 12’0 to 9° 21’0N. similarly way forests in Ethiopia in general and dry Afromontane, in The altitude of Asabot Mountain ranges from 1087 to 2474 meters above particular, have been affected by climatic and anthropogenic factors [5- sea level (Table 1). 9]. The assessment of forest cover change history of Ethiopia indicated reduction from 40% to less than 2.8% in the 19th century with current Asabot mountain forest is part of evergreen dry Afromontane improvement to 15% [10,11]. The shifted vegetation shared half by ecology; characterized by average minimum (451.2 ml) and maximum Afromontane forest or mostly by dry Afromontane forests [1]. The (1055.5 ml) annual precipitation, mean minimum (11.9°C) and maximum (31.9°C) temperature, respectively according to metrological climatic characterization of Afromontane in Ethiopia distinguished by data for the last ten years (Figure 2). moisture than surrounding lowland [12,13]. The agroecology of dry Afromontane is described by an altitude range from 1500-3400 m above The topography of the study site was raged mountain characterized sea level; 700-1100 mm mean annual rainfall; and 14-25°C average by flat (1577 hectare) to rolling (803 hectares) (Table 1 and Figure 3). annual temperature with coverage of distributed highland of central, Asabot mountain ascends from 1080-2447 meter above sea level with northern, eastern and southern parts of Ethiopia [5,14,15]. This suitable immediate facing (aspect) change. However, the vegetation samples for human inhabitation accompanied by sedentary agriculture, extensive collected from an altitude range of 1778 to 2404 meter above sea level in cattle herding activities and socio-political instability. Dry Afromontane order to reduce edge effects and due to the scope of the study. ecology exposed to heavy deforestation, forest fragmentation and loss of biodiversity, impoverishment ecosystems and climate change vulnerability [16]. Indeed, they are a very important in-situ biodiversity *Corresponding author: Tura TT, Ph.D. fellow, Center for Environmental science, Addis Ababa University, Ethiopia, Tel: +251-111-239 472; E-mail: tulutollatura@ conservation spot [17]. In view, the study has been conducted valued on gmail.com addressing plant community variation along an environmental gradient Received October 30, 2017; Accepted December 05, 2017; Published December of Asabot mountain forest. 10, 2017 Though the current progress made on Asabot mountain forest Citation: Tura TT, Soromessa T, Leta S, Argaw M (2017) Plant Community demarcation as national wildlife protection sanctuary, the forest Composition and Structure of Asabot Dry Afromontane Forest, West Harare Zone, Ethiopia. J Biodivers Endanger Species 5: 202. doi: 10.4172/2332-2543.1000202 is currently continuously exploited by surrounding people for construction woodcutting, timber harvesting, charcoal production, Copyright: © 2017 Tura TT, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted firewood collection and other. Indeed, the plant community, floristic use, distribution, and reproduction in any medium, provided the original author and composition, and structure were not well studied yet. Therefore, the source are credited. J Biodivers Endanger Species, an open access journal Volume 5 • Issue 4 • 1000202 ISSN: 2332-2543 Citation: Tura TT, Soromessa T, Leta S, Argaw M (2017) Plant Community Composition and Structure of Asabot Dry Afromontane Forest, West Harare Zone, Ethiopia. J Biodivers Endanger Species 5: 202. doi: 10.4172/2332-2543.1000202 Page 2 of 12 Sampling design slope not strictly followed. The 20 m × 20 m (400 2m ) size sampling quadrats of 150 m and 100 m distance between transect and quadrat, The vegetation sampling method was chosen the mixed spatial respectively used. Inside the 20 m × 20 m quadrat five, 5 m × 5 m stratified-random procedure to ensure a full coverage of environmental subplots, one at each corner and one at the center of the main quadrat variation and habitat heterogeneity within the altitudinal gradient were set to sample shrubs. The seedling and sapling data were collected following Kent and Coker [18] and Muller-DuBois and Eilenberg [19]. from five 2 m × 2 m subplots, one at each corner and one at the center The direction of sampling quadrats was not followed strict procedure of the main plot. The diameter of all woody plants was recorded using due to the complexity of the mountain. The quadrats covered clustered diameter tape while height was measured using Hagan hypsometer and altitude of the study sites (lower, middle and upper) but aspect and Clinometer. The diameter of normal individual trees was measured at Figure 1: Map of Asabot dry Afromontane forest. Altitude Area in ha Slope Area in ha Aspect Area in ha 1087--1200 494 0--2 1577 North 4617 1201--1400 3688 3--8 6644 East 4697 1401--1600 7726 9--15 2781 South 3417 1601--1800 2360 16--32 4710 West 3776 1801--2000 1270 33--59 803 North 4617 2001--2200 676 - - - - 2201--2474 297 - - - - Table 1: Description of Asabot mountain forest. Figure 2: Mean annual precipitation and mean annual maximum temperature trends of the study site, 2004-2015. J Biodivers Endanger Species, an open access journal Volume 5 • Issue 4 • 1000202 ISSN: 2332-2543 Citation: Tura TT, Soromessa T, Leta S, Argaw M (2017) Plant Community Composition and Structure of Asabot Dry Afromontane Forest, West Harare Zone, Ethiopia. J Biodivers Endanger Species 5: 202. doi: 10.4172/2332-2543.1000202 Page 3 of 12 breast height if the tree branched at breast height; and the diameter was image [18]. The specimens of all woody plant were pressed, dried and measured separately and averaged if the tree was multi-stemmed. The brought to the National Herbarium of Addis Ababa University for diameter was measured individual and recorded if the tree buttressed identification and storage. The wood plant nomenclature was followed at breast height. The diameter was also measured above or below the Flora of Ethiopia and Eritrea book (FEE). breast height at normal shape; and if the tree was angled or slopes, the diameter was measured opposite direction of the inclination (Figure 4). Plant community analysis Where topographic features made it difficult to measure trees and The dendrogram wood plant community cluster was analyzed based shrubs, height was estimated visually. The environmental variables such on cover abundance data of species composition in their hierarchical as altitude, slope, aspects and geographical coordinates were measured classification. The plant community types were named after two or three for each plots using Garmin Geographical Position System and satellite dominant species selected using the relative magnitude of their mean Figure 3: Altitude, slope and aspect description of asabot mountain forest. Figure 4: Sample plot distribution. J Biodivers Endanger Species, an open access journal Volume 5 • Issue 4 • 1000202 ISSN: 2332-2543 Citation: Tura TT, Soromessa T, Leta S, Argaw M (2017) Plant Community Composition and Structure of Asabot Dry Afromontane Forest, West Harare Zone, Ethiopia.